Extended Data Fig. 7: Comparison of bison NHA2 ΔN structures in detergent and nanodiscs.
From: Structure, mechanism and lipid-mediated remodeling of the mammalian Na+/H+ exchanger NHA2
a. Electrostatic surface representation of the side view of the outward-facing NHA2 homodimer highlighting the large, intracellular gap between protomers and intracellular positively-charged surface in detergent (left) that is closed upon TM –1 rearrangement in nanodiscs incorporated with PI lipids (right). b. The cryo EM density for the nanodisc surrounding NHA2ΔN from the side and top, and the manually placed bison NHA2ΔN structure determined in detergent. c. Cartoon representation on the dimer interface showing the polar contacts between the K168, H169, K170 and W171 residues, in the end of TM3 of one protomer (green sticks, labeled), and the identical residues from the neighboring protomer (green sticks, labeled with ‘), with the PI lipids located in between these residues at the center of the dimer interface. Also interacting with R176 of T3 is E406 (TM10), which might stabilize the outward-facing cavity leading the ion-binding, interaction encircled. Modelled lipids are shown as sticks for, PI lipid headgroups (red), cholesterol located on extracellular half of the protein (yellow), and PI tails (gray). Cryo-EM density is shown as blue mesh around the mentioned residues and ligands.
